Grain stirring apparatus

ABSTRACT

A grain stirring device includes an endless flexible conveyor which is mounted on a supporting structure for movements about a circuitous path and for rotation of the circuitous path on a vertical axis within a circular grain drying bin and power means is provided to impart the circuitous and rotational movements upon proper energization of the power means.

United States Patent Murphy 7 [451 Sept. 26, 1972 [54] GRAIN STIRRINGAPPARATUS [72] Inventor: David M. Murphy, RFD 4,

Mason City, Iowa 50401 [22] Filed: Aug. 13, 1971 21 Appl. No.: 171,421

[52] US. Cl ..259/114, 259/46 [51] Int. Cl. ..B0lf 5/26 [58] Field ofSearch ..259/99, 102, 111, 37, 40, 19,

[56] References Cited UNITED STATES PATENTS 3,156,541 11/1964 Kalke..-.259/111 3,251,582 5/1966 Murphy ..259/l11 3,294,491 12/ 1 966 Brown..259/ l 02 3,412,982 11/1968 Feteri ..259/37 3,445,091 5/1969 Jackson..259/1 1 1 3,580,549 5/1971 Murphy ..259/1 11 Primary Examiner-RobertW. Jenkins Attorney-Merchant & Gould [5 7] ABSTRACT A grain stirringdevice includes an endless flexible conveyor which is mounted on asupporting structure for movements about a circuitous path and forrotation of the circuitous path on a vertical axis within a circulargrain drying bin and power means is provided to impart the circuitousand rotational movements upon proper energization of the power means.

7 Claims, 7 Drawing Figures PATENTEDsms m2 SHEET 1 0F 2 PATENTED EP 26 93.693.944

sum 2 0F 2 .F'i'a. Z

INVENTOR.

DAVID M MURPHY A7 TORNE Y5 1 GRAIN STIRRING APPARATUS BACKGROUND OF THEINVENTION 1. Field of the Invention:

It is current practice to dry grain or other likematerials by placingsame in a cylindrical container or bin and forcing heated air upwardlytherethrough. Such drying operations have resulted in various problemsand the need to develop other methods to more efficiently dry the grain.An example of two methods of drying grain are batch drying and layerdrying. Neither of the abovementioned drying methods are economicallyacceptable since both require considerable effort and man hours of laborto complete. Additionally, problems such as uneven drying, incompletedrying and crusting of the upper surface of the grain have furthercomplicated such drying operations with the result that excessive insectinfestation and/or spoilage and expense have occurred with the use ofthe above methods. A more acceptable method of drying grain has beendeep bed drying in which the bin is substantially filled with grain anda mixing device, such as that disclosed in my prior US. Pat. No.3,251,582, issued May 17, 1966, is used to constantly stir or mix thegrain throughout the drying cycle. Such devices are normally constructedto provide a mixing device which automatically travels a predeterminedpath circumferentially and radially within the bin, during the dryingcycle, to overcome the above problems.

2. Description of the Prior Art:

Present prior art stirring devices present problems in that, due toconstruction, such devices have not been able to sufficiently'mix orstir the grain or material in close proximity to the bin wall and arerather complicated and expensive .to manufacture. Such incoinpletestirring or mixing results in a longer drying period and the need forspecial manual adjustments to the stirring device to cause same toremain in the vicinity of the outer circular wall of the bin for alonger period of time. This is necessary due to increased moisture orcondensation adjacent the interior of the metal bin wall which createsadditional drying problems. Causing the stirring device to remain in thevicinity of the outer bin wall presents an additional problem in thatthe remainder of the grain or material in the bin is exposed to the flowof heated air for an excessive period of time and the grain-ormaterial'is overheated or over-dried. If such adjustments are not made,the grain or material near the outer bin wall is not dried sufficientlyand infestation and/or spoilage soon occurs. Additionally, that portionof the grain lying adjacent the bottom wall of the bin is, even undernormal conditions, subjected to a much greater degree of heat than thatlying thereabove since the heated air cools as it progresses upwardlythrough the grain. Prior art stirring devices have failed to provide forproportionally greater circulation of grain in this area with the resultthat this grain may be over-heated or over-dried relative to theremainder of the grain thereabove within the bin.

SUMMARY OF THE INVENTION The present invention is constructed of anendless flexible conveyor supported in the grain drying bin formovements of the conveyor about a circuitous path which lies in a planeextending generally radially from the vertical axis to the circularouter wall between the upper and lower wall of the drying bin and forrotary movements of the support means on a vertical axis coaxiallydisposed with respect to the vertical axis of the drying bin. Powermeans is operatively mounted to impart the circuitous movements to theconveyor and independent power means imparts rotational movement to thesupport means and conveyor mounted thereon during circuitous movementsof the conveyor.

It is an object of the present invention to provide a grain stirringdevice which stirs and/or mixes the grain throughout the bin in which itis being dryed a proportionate amount to permit drying of such grain ina minimum of time and with but a minimum of labor.

It is another object of the present invention to provide a device of theabove character which is easily in stalled in cylindrical grain dryingbins presently manufactured, durable in use and extremely dependable inoperation.

It is a further object of the present invention to provide a device ofthe character above described which consists of relatively few movingparts, requires a minimum of skill and manual adjustments to operate andis relatively inexpensive to manufacture.

These and other important objects will become apparent to those skilledin the art upon reference to the accompanying specification, claims anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings, whereinlike characters indicate like parts throughout the figures:

FIG. 1 is a view in vertical section of a grain drying bin illustratingthe present invention in side elevation and mounted thereon, portionsthereof being broken away and shown in section;

FIG. 2 is a fragmentary view in horizontal section as seen generallyfrom the line 22 in FIG. 1 on an enlarged scale;

FIG. 3 is an enlarged view in vertical section as seen generally fromthe line 3+3 of FIG. 1, portions thereof broken away;

FIG. 4 is a fragmentary view in vertical section as seen generally fromthe line 4-4 of FIG. 3;

FIG. 5 is a view in horizontal section on an enlarged scale as seengenerally from the line 5-5 of FIG. 4;

FIG. 6 is an enlarged fragmentary view in horizontal section as seenfrom the line 6--6 of FIG. 4; and

FIG. 7 is a schematic diagram of the electrical circuit utilized tocontrol the supply of electrical energy to the drive motors of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawings, FIG. 1 shows a vertical sectional view through aconventional circular grain drying bin indicated generally by thenumeral 10. Drying bin 10 includes a circular outer wall 11 supported ona foundation 12. A frusto-conical upper wall or roof l3 overlies thecircular outer wall 1 l and a perforate bottom wall 14 is positioned inthe bin in upwardly spaced relation to the foundation 12. The perforatebottom wall 14 and adjacent portion of wall 11 serve to define, with thefoundation 12, a plenum chamber 15. A conduit 15' leading from a sourceof heated air under pressure, not shown, communicates with the plenumchamber 15 and introduces heated air through the perforate bottom wall14 to grain 16 stored within the drying bin 10. Openings 17, 18, formedin the upper wall 13, serve the functions of venting the heated airpassing through grain 16 from the bin 10, providing openings for theintroduction of grain 16 and permitting visual inspection of theinterior of the bin 10.

A screw conveyor 20 is positioned within the plenum chamber 15 and hasone end thereof communicating with an opening 21 formed centrally in theperforate bottom wall 14. Screw conveyor 20 leads laterally from theopening 21 to the exterior of the bin and is utilized to remove grain 16from the interior of the bin 10 when it is so decided. Drying of grain16 within the drying' bin 10 is normally accomplished by introducingheated air under pressure into the plenum chamber 15, upwardly throughthe perforate bottom wall 14, the grain 16 and finally out through theopening 17, 18.

In order to avoid the problems heretofor disclosed in the variousmethods of drying grain and the problems inherent in the prior artdevices for stirring such grain, there is provided a grain stirringapparatus hereinafter identified generally by the numeral 30. Stirringapparatus 30 includes a flexible endless conveyor 31 preferably formedfrom an endless link chain. Support means mounting the conveyor 31 formovements about a circuitous path of travel within the drying bin 10 andfor rotation of the circuitous path within the drying bin 10, as will bedescribed in greater detail hereinafter, is indicated generally by thenumeral 35. Support means 35 includes a tubular element 36 mounted as at37, 38 for rotational movements on a vertical axis generally coaxiallydisposed with respect to the vertical axis of the drying bin 10. A firstportion 39 extends radially from the tubular element 36 adjacent thebottom wall 14 of drying bin 10 and terminates at its radially outer endin -a second portion 40. Second portion 40 extends from the firstportion 39 in a vertically upward direction, adjacent and parallel tothe circular outer wall 11, to a point wherein it terminates adjacentthe juncture of the upper wall 13 with the side wall 11. A rigidconnecting link 41 connects the upper end of the portion 40 to the upperend of the tubular element 39.

As shown, particularly in FIG. 1, vertically disposed tubular element36, together with first and second portions 39, 40, cooperate to definea guide track for conveyor 31. Such guide track guides the conveyor 31in the above circuitous path of travel which lies in a plane thatextends radially from the vertical axis to the circular outer wall 11and generally between the upper and lower walls 13, 14, respectively, ofthe drying bin 10. As shown, portions 39, 40 are formed to have agenerally rectangular C-shaped crosssectional configuration which opensin the direction of rotation of the stirring apparatus 30, indicated bythe arrow in FIG. 2, to define a longitudinally extended slot 42. In thepresent application such direction is shown as being counterclockwisefor exemplatory purposes only, it being understood that, by slightmodification, such grain drying device 30 may be constructed to operatein either clockwise or counterclockwise directions of rotation. Aplurality of paddle-like elements 43 are secured to the conveyor 31, atlongitudinally spaced points thereof, in a manner to project laterallytherefrom through the slot 42 and travel along such slot 42 during theabove-mentioned circuitous movements. The paddle-like elements 43 act toengage and move grain adjacent to the portions 39, 40 in the directionindicated by the arrows shown in FIG. 1. Thus, as the conveyor 31 movesin its circuitous path of travel the grain 16 adjacent the guide portion39, in the area of the perforate bottom wall 14, is moved radiallyoutwardly toward the circular outer wall 11 and the grain 16 adjacentthe guide portion 40 and the circular outer wall 11 is moved verticallyupwardly toward the top wall 13. In this manner, it will be seen thatrotation of the portions 39, 40 about the axis of the tubular element36, together with the above-described circuitous movements of theconveyor 31, results in a circulation of the grain 16 within the bin 10throughout 360 of rotation of the grain stirring device 30 about thevertical axis of the grain drying bin 10. It will be noted thatpositioning of the portions 39, 40 and conveyor 31 guided thereby, asabove described, assures that grain 16 adjacent the bottom wall 14 isadequately circulated or moved in a greater proportion and amount thanthat grain 16 above it. Thus, grain 16 adjacent the bottom wall 14 isprevented from over-exposure to the heated air forced through the grain16 from the plenum chamber 15 and consequently damage thereto. Inaddition, since excessive moisture problems may exist adjacent outerwall 11, positioning of portions 39, 40 and conveyor 31, as described,proportionally increases the circulation of grain 16 immediatelyadjacent wall 11 relative to grain l6 radially inwardly from portion 40.

To facilitate the movement of the conveyor 31 in its circuitous path oftravel, with a minimum of frictional resistance, portion 39 is formed toinclude a radius 45 at its point of juncture with tubular element 36 anda radius 46 at its point of juncture with portion 40. A radius 47 islikewise formed at the upper end of portion 40. In order to complete acircuitous path of travel con veyor 31 extends from the radius 47 oversprockets 48, 49 carried by the supporting means 35 adjacent the upperend of tubular element 36. Sprocket 49 serves to guide the endless chainof the conveyor 31, together with the paddle-like elements 43, formovement downwardly through the interior of the tubular element 36wherein same is then guided into movement radially outwardly toward thewall 1 1 over radius 45, along portion 39, over radius 46 and upwardlyalong portion 40 to radius 47. This arrangement guides the paddle-likeelements 43 so they pass downwardly through the interior of the tubularelement 36, and do not engage the grain 16. If such engagement were tooccur, undue restrictive forces would retard movement of the conveyor 31downwardly through the grain 16 resulting in undue wear and/or damage tothe conveyor 31 or parts associated therewith and the requirement ofexpensive heavy-duty power means, together with expensive, heavy-dutyconstruction of the supporting structure 35, for imparting suchcircuitous movements to the conveyor 31.

For the purpose of imparting the above-described circuitous movements tothe conveyor 31 an electrically operated gearhead motor 55 is mountedadjacent the upper end of the tubular element 36. A power output shaft56 of the gear-head motor 55 is rigidly affixed to the sprocket 49 toimpart rotation thereto upon energization of the gearhead motor 55 andconsequently circuitous movements to the conveyor 31. Sprocket member 48functions as an idler and is adjustable in a direction to provide thecorrect amount of tension to the conveyor 31 to assure drivingengagement of the sprocket 49 with the conveyor 31.

Independent power means, indicated generally by the numeral 60, forimparting movements to the support means 35 about the vertical axis ofthe grain drying bin includes an electrically operated gearhead motor61. As shown, motor 61 is secured to the support means 35 generally atthe level of the upper end of the portion 40 adjacent the outer wall 11of the drying bin 10; A power output shaft 62 has rigidly affixedthereto a grooved drive wheel 63 which rests upon and has drivingengagement with a circular track 64. Track 64 extends circumferentiallyof the drying bin 10 and is affixed to the circular outer wall 11adjacent the upper wall 13. A generally vertically downwardly spacedroller element 65 is mounted on and carried by the support means 35 in amanner to underlie the circular track 64 and thus maintain the drivewheel 63 in driving engagement with the track 64 at all times during its360 degrees of travel within the circular drying bin 10.

As seen particularly in FIG. 7 of the drawings, electric motors 55, 61are adapted to be connected to a source of electrical power, not shown,by means of a plurality of slip rings 70 and a switching mechanism 71.Slip rings 70 are normally mounted within a rectangular housing 73positioned adjacent to the upper end of the tubular element 36 andadapted to mount and position the slip rings 70 such that the rotaryaxis thereof is generally coaxial with respect to the rotary axis of thetubular element 36. It will thus be seen that circuitous movements ofthe conveyor 31, through energization of the gearhead motor 55 androtational movements of the support means 35, through energization ofthe motor 61, are caused by closing the switch 71 to supply a flow ofelectrical energy through the slip rings 70 from the source of power,not shown, to the motors 55, 61.

During grain drying operations of the grain stirring device 30 verticalportion 40, in its circumferential movement, may be excessivelydeflected from a vertical position by engagement with variousobstructions within the drying bin 10 which tend to restrictcircumferential movement thereof. By way of example, an obstruction maybe catagorized as any material present in the drying bin 10 which wouldpresent undue restriction to movement of the support means 35 in itscircumferential movement. It will be appreciated that that portion ofthe support means 35 adjacent the radius 46 may encounter moredifficulty in passing through the grain 16 than that portion of guideportion 40 adjacent radius 47 due to the weight or packing of the grainadjacent bottom wall 14. Thus, attempts of the device 30 to movecircumferentially within the bin 10 when filled with grain 16 may resultin excessive deflection of the lower end of guide portion 40 rearwardlywith respect to the upper end thereof and the direction of travel. Itwill also be appreciated that certain other conditions may cause heavygrain concentration or density at isolated spots and the termobstruction is meant to apply to any and all conditions which may bepresent to unduly restrict movement of portions 39 or 40 so as toexcessively deflectguide portion 40 in an amount to 7 cause damage tostirring device 30.

For the purpose of protecting against damage to the stirring deviceduring the occurrence of such deflection, for example a deflection ofmore than 5 degrees, means is provided for disabling the gearhead motor61 until the guide portion 40 returns to a lesser degree of deflection(a deflection of less than 5). Such means includes a mercury switch 75mounted on the upper end of the support means adjacent the upper end ofthe guide portion 40. A mounting bracket 76 is adapted to adjustablymount the mercury switch 75 so as to sense a desired degree ofdeflection of the portion 40. For the present example the above noteddeflection of more than 5 of the guide portion will position the switch75 to-terminate the supply of electrical energy to the gearhead motor 61and thus terminate movement of the portions 39 and 40 circumferentiallyof the drying bin 10. Since the supply of electrical energy to only oneof the gearhead motors 61 has been terminated, motor 55 continues tooperate and impart movement to the conveyor 31 along its circuitous pathof travel.

Normally obstructions, such as grain 16, within the container 10engaging the upper end of the portion 40 i does not usually deflect suchportion a sufflcient degree to cause the motor 61 to become disabled,but merely causes slippage between the drive wheel 63 and circular track64 until such obstruction or grain 16 has been moved from the path oftravel of conveyor 31 by the paddle-like elements 43. However, shouldthe obstruction be positioned at a lower elevation so as to be engagedat a lower elevation on the guide portion 40 or by the guide portion 39,deflection of the guide portion 40 from the vertical could occur and themercury switch would move to a position wherein the motor 61 would bedeenergized to terminate movement of the portion 40 circumferentially ofthe bin 10. Since the conveyor 31 would continue to move in itscircuitous path of travel, paddle-like elements 43 would continue toengage the material restricting the movements of guide portion 40circumferentially of the bin 10 until the guide portion 40 would againreturn to its normal position of less than 5. Upon removal of therestriction switch 75 would again be positioned to energize the motor 61and movement of the guide portion 40 circumferentially of the storagebin 10 would resume. It will be appreciated that such a start-stop cycleof circumferential movement may occur many times as the conveyor 31 andsupporting structure thereof moves circumferentially of the bin 10,resulting in a walkingtype motion of the stirring apparatus 30. Such adisabling device as the mercury switch 75 obviously prevents anyexcessive twisting of the supporting structure 35 during theabove-described deflection which could well result in damage thereto andconsequently inoperativeness of the stirring mechanism 30. By referenceto the foregoing description it will be seen that a grain stirringapparatus has been provided which is extremely simplified inconstruction, thus requiring little or no maintenance through extendedperiods of operation. In addition, a grain stirringapparatus has beenprovided which overcomes the inherent problems present in prior artgrain stirring devices now manufactured so as to more efficiently reducethe drying time and expense of such grain drying operations.

While a specific embodiment of a grain stirring apparatus is illustratedand described, it should be understood that further modifications andimprovements will occur to those skilled in the art. I desire it to beunderstood, therefore, that this invention is not limited to theparticular structure shown and intend in the appended claims to coverall modifications which do no depart from the spirit and scope of thisinvention.

What is claimed is:

1. Grain stirring apparatus for use in a grain drying bin having acircular outer wall, a top wall and a bottom wall, said grain stirringapparatus comprising:

a. a flexible endless conveyor;

b. support means mounting said conveyor for movement about a circuitouspath and for rotation of the circuitous path within said said dryingbin; and

c. power means for providing said circuitous movement and saidrotational movement upon proper energization thereof.

2. Grain stirring apparatus for use in a grain drying bin having acircular outer wall, a top wall and a bottom wall, said grain stirringapparatus comprising:

a. a flexible endless conveyor;

b. support means for said conveyor;

0. said flexible endless conveyor being mounted on said support meansfor movements in a circuitous path of travel;

d. means mounting said support means for rotation on a vertical axisgenerally parallel to the vertical axis of the grain drying bin;

e. power means operatively mounted to impart said circuitous movementsto said conveyor; and

f. independent power means for imparting said rotational movement tosaid support means.

3. The structure of claim 2 in which said circuitous path of travel liesin a plane which generally extends radially from the vertical axis tothe circular outer wall generally between the upper and lower wall ofthe grain drying bin.

4. The structure of claim 2 in which said support means mounting saidconveyor for movements in a circuitous path includes:

a. a vertically disposed tubular element;

b. a first guide portion extending radially from said tubular elementmounting said flexible conveyor for movements generally radiallyoutwardly adjacent the bottom wall of the grain drying bin; and

c. a second guide portion extending vertically from the radially outerend of said first portion and mounting said conveyor for movementsvertically upwardly adjacent the circular outer wall of said graindrying bin.

5. The structure of claim 4 in further combination with means fordisabling said independent power means responsive to deflection of saidsecond portion of said support means adjacent said circular outer wall agiven amount of degrees from the vertical during circumferentialmovement of said portion relative to said circular outer wall.

6. The structure of claim 5 in which said independent power meansincludes an electrically operated motor and in which said means fordisabling said independent power means is a mercury switch adjustablymounted on said second portion of said support means adjacent the u perend thereof, said mercury switch being moun ed to terminate the supplyof electrical energy to said electrically operated motor responsive todeflection of said second portion of said support means a given amountof degrees from the vertical during said circumferential movement ofsaid second portion.

7. The structure of claim 2 in which said tubular element defines thevertical axis of rotation of said support means and is coaxiallydisposed with respect to the vertical axis of the grain drying bin.

1. Grain stirring apparatus for use in a grain drying bin having acircular outer wall, a top wall and a bottom wall, said grain stirringapparatus comprising: a. a flexible endless conveyor; b. support meansmounting said conveyor for movement about a circuitous path and forrotation of the circuitous path within said said drying bin; and c.power means for providing said circuitous movement and said rotationalmovement upon proper energization thereof.
 2. Grain stirring apparatusfor use in a grain drying bin having a circular outer wall, a top walland a bottom wall, said grain stirring apparatus comprising: a. aflexible endless conveyor; b. support means for said conveyor; c. saidflexible endless conveyor being mounted on said support means formovements in a circuitous path of travel; d. means mounting said supportmeans for rotation on a vertical axis generally parallel to the verticalaxis of the grain drying bin; e. power means operatively mounted toimpart said circuitous movements to said conveyor; and f. independentpower means for imparting said rotational movement to said supportmeans.
 3. The structure of claim 2 in which said circuitous path oftravel lies in a plane which generally extends radially from thevertical axis to the circular outer wall generally between the upper andlower wall of the grain drying bin.
 4. The structure of claim 2 in whichsaid support means mounting said conveyor for movements in a circuitouspath includes: a. a vertically disposed tubular element; b. a firstguide portion extending radially from said tubular element mounting saidflexible conveyor for movements generally radially outwardly adjacentthe bottom wall of the grain drying bin; and c. a second guide portionextending vertically from the radially outer end of said first portionand mounting said conveyor for movements vertically upwardly adjacentthe circular outer wall of said grain drying bin.
 5. The structure ofclaim 4 in further combination with means for disabling said independentpower means responsive to deflection of said second portion of saidsupport means adjacent said circular outer wall a given amount ofdegrees from the vertical during circumferential movement of saidportion relative to said circular outer wall.
 6. The structure of claim5 in which said independent power means includes an electricallyoperated motor and in which said means for disabling said independentpower means is a mercury switch adjustably mounted on said secondportion of said support means adjacent the upper end thereof, saidmercury switch being mounted to terminate the supply of electricalenergy to said electrically operated motor responsive to deflection ofsaid second portion of said support means a given amount of degrees fromthe vertical during said circumferential movement of said secondportion.
 7. The structure of claim 2 in which said tubular elementdefines the vertical axis of rotation of said support means and iscoaxially disposed with respect to the vertical axis of the grain dryingbin.